diff options
author | Giuseppe D'Angelo <giuseppe.dangelo@kdab.com> | 2020-04-19 19:56:18 +0200 |
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committer | Giuseppe D'Angelo <giuseppe.dangelo@kdab.com> | 2020-09-03 07:00:31 +0200 |
commit | 25351dcc549f1daddf5e2ae8a242191174342a3e (patch) | |
tree | 97436200219470e7eee4096038e4da6e8df06835 /src/corelib/global/qnamespace.h | |
parent | f03b2f7711e3a0e90fb21672273959a2a9ed1c38 (diff) |
Long live QKeyCombination!
C++20 via P1120 is deprecating arithmetic operations between
unrelated enumeration types, and GCC 10 is already complaining.
Hence, these operations might become illegal in C++23 or C++26 at
the latest.
A case of this that affects Qt is in key combinations: a
QKeySequence can be constructed by summing / ORing modifiers and a
key, for instance:
Qt::CTRL + Qt::Key_A
Qt::SHIFT | Qt::CTRL | Qt::Key_G (recommended, see below)
The problem is that the modifiers and the key belong to different
enumerations (and there's 2 enumerations for the modifier, and one
for the key).
To solve this: add a dedicated class to represent a combination of
keys, and operators between those enumerations to build instances
of this class.
I would've simply defined operator|, but again docs and pre-existing
code use operator+ as well, so added both to at least tackle simple
cases (modifier + key).
Multiple modifiers create a problem: operator+ between them yields
int, not the corresponding flags type (because operator+ is not
overloaded for this use case):
Qt::CTRL + Qt::SHIFT + Qt::Key_A
\__________________/ /
int /
\______________/
int
Not only this loses track of the datatypes involved, but it would
also then "add" the key (with NO warnings, now its int + enum, so
it's not mixing enums!) and yielding int again.
I don't want to special-case this; the point of the class is
that int is the wrong datatype. Everything works just fine when
using operator| instead:
Qt::CTRL | Qt::SHIFT | Qt::Key_A
\__________________/ /
Qt::Modifiers /
\______________/
QKeyCombination
So I'm defining operator+ so that the simple cases still work,
but also deprecating it.
Port some code around Qt to the new class. In certain cases,
it's a huge win for clarity. In some others, I've just added
the necessary casts to make it still compile without warnings,
without attempting refactorings.
[ChangeLog][QtCore][QKeyCombination] New class to represent
a combination of a key and zero or more modifiers, to be used
when defining shortcuts or similar.
[ChangeLog][Potentially Source-Incompatible Changes] A keyboard
modifier (such as Qt::CTRL, Qt::AltModifier, etc.) should be
combined with a key (such as Qt::Key_A, Qt::Key_F1, etc.) by using
operator|, not operator+. The result is now an object of type
QKeyCombination, that stores the key and the modifiers.
Change-Id: I657a3a328232f059023fff69c5031ee31cc91dd6
Reviewed-by: Volker Hilsheimer <volker.hilsheimer@qt.io>
Diffstat (limited to 'src/corelib/global/qnamespace.h')
-rw-r--r-- | src/corelib/global/qnamespace.h | 156 |
1 files changed, 156 insertions, 0 deletions
diff --git a/src/corelib/global/qnamespace.h b/src/corelib/global/qnamespace.h index a531bc627b..0c4b4fc8bf 100644 --- a/src/corelib/global/qnamespace.h +++ b/src/corelib/global/qnamespace.h @@ -1,6 +1,7 @@ /**************************************************************************** ** ** Copyright (C) 2020 The Qt Company Ltd. +** Copyright (C) 2020 Klaralvdalens Datakonsult AB, a KDAB Group company, info@kdab.com, author Giuseppe D'Angelo <giuseppe.dangelo@kdab.com> ** Contact: https://www.qt.io/licensing/ ** ** This file is part of the QtCore module of the Qt Toolkit. @@ -1094,6 +1095,8 @@ namespace Qt { ALT = Qt::AltModifier, MODIFIER_MASK = KeyboardModifierMask, }; + Q_DECLARE_FLAGS(Modifiers, Modifier) + Q_DECLARE_OPERATORS_FOR_FLAGS(Modifiers) enum ArrowType { NoArrow, @@ -1785,6 +1788,9 @@ namespace Qt { Q_ENUM_NS(SortOrder) Q_ENUM_NS(CaseSensitivity) Q_FLAG_NS(MatchFlags) + Q_ENUM_NS(Modifier) + Q_FLAG_NS(Modifiers) + Q_ENUM_NS(KeyboardModifier) Q_FLAG_NS(KeyboardModifiers) Q_FLAG_NS(MouseButtons) Q_ENUM_NS(WindowType) @@ -1863,6 +1869,156 @@ public: static bool activateCallbacks(Callback, void **); }; +class QKeyCombination +{ + int combination; + +public: + constexpr /* implicit */ QKeyCombination(Qt::Key key = Qt::Key_unknown) noexcept + : combination(int(key)) + {} + + constexpr explicit QKeyCombination(Qt::Modifiers modifiers, Qt::Key key = Qt::Key_unknown) noexcept + : combination(int(modifiers) | int(key)) + {} + + constexpr explicit QKeyCombination(Qt::KeyboardModifiers modifiers, Qt::Key key = Qt::Key_unknown) noexcept + : combination(int(modifiers) | int(key)) + {} + + constexpr Qt::KeyboardModifiers keyboardModifiers() const noexcept + { + return Qt::KeyboardModifiers(combination & Qt::KeyboardModifierMask); + } + + constexpr Qt::Key key() const noexcept + { + return Qt::Key(combination & ~Qt::KeyboardModifierMask); + } + + static constexpr QKeyCombination fromCombined(int combined) + { + QKeyCombination result; + result.combination = combined; + return result; + } + + constexpr int toCombined() const noexcept + { + return combination; + } + +#if QT_DEPRECATED_SINCE(6, 0) + QT_DEPRECATED_VERSION_X(6, 0, "Use QKeyCombination instead of int") + constexpr /* implicit */ operator int() const noexcept + { + return combination; + } +#endif + + friend constexpr bool operator==(QKeyCombination lhs, QKeyCombination rhs) noexcept + { + return lhs.combination == rhs.combination; + } + + friend constexpr bool operator!=(QKeyCombination lhs, QKeyCombination rhs) noexcept + { + return lhs.combination != rhs.combination; + } +}; + +Q_DECLARE_TYPEINFO(QKeyCombination, Q_MOVABLE_TYPE); + +constexpr QKeyCombination operator|(Qt::Modifier modifier, Qt::Key key) noexcept +{ + return QKeyCombination(modifier, key); +} + +constexpr QKeyCombination operator|(Qt::Modifiers modifiers, Qt::Key key) noexcept +{ + return QKeyCombination(modifiers, key); +} + +constexpr QKeyCombination operator|(Qt::KeyboardModifier modifier, Qt::Key key) noexcept +{ + return QKeyCombination(modifier, key); +} + +constexpr QKeyCombination operator|(Qt::KeyboardModifiers modifiers, Qt::Key key) noexcept +{ + return QKeyCombination(modifiers, key); +} + +constexpr QKeyCombination operator|(Qt::Key key, Qt::Modifier modifier) noexcept +{ + return QKeyCombination(modifier, key); +} + +constexpr QKeyCombination operator|(Qt::Key key, Qt::Modifiers modifiers) noexcept +{ + return QKeyCombination(modifiers, key); +} + +constexpr QKeyCombination operator|(Qt::Key key, Qt::KeyboardModifier modifier) noexcept +{ + return QKeyCombination(modifier, key); +} + +constexpr QKeyCombination operator|(Qt::Key key, Qt::KeyboardModifiers modifiers) noexcept +{ + return QKeyCombination(modifiers, key); +} + +#if QT_DEPRECATED_SINCE(6, 0) +QT_DEPRECATED_VERSION_X(6, 0, "Use operator| instead") +constexpr QKeyCombination operator+(Qt::Modifier modifier, Qt::Key key) noexcept +{ + return QKeyCombination(modifier, key); +} + +QT_DEPRECATED_VERSION_X(6, 0, "Use operator| instead") +constexpr QKeyCombination operator+(Qt::Modifiers modifiers, Qt::Key key) noexcept +{ + return QKeyCombination(modifiers, key); +} + +QT_DEPRECATED_VERSION_X(6, 0, "Use operator| instead") +constexpr QKeyCombination operator+(Qt::KeyboardModifier modifier, Qt::Key key) noexcept +{ + return QKeyCombination(modifier, key); +} + +QT_DEPRECATED_VERSION_X(6, 0, "Use operator| instead") +constexpr QKeyCombination operator+(Qt::KeyboardModifiers modifiers, Qt::Key key) noexcept +{ + return QKeyCombination(modifiers, key); +} + +QT_DEPRECATED_VERSION_X(6, 0, "Use operator| instead") +constexpr QKeyCombination operator+(Qt::Key key, Qt::Modifier modifier) noexcept +{ + return QKeyCombination(modifier, key); +} + +QT_DEPRECATED_VERSION_X(6, 0, "Use operator| instead") +constexpr QKeyCombination operator+(Qt::Key key, Qt::Modifiers modifiers) noexcept +{ + return QKeyCombination(modifiers, key); +} + +QT_DEPRECATED_VERSION_X(6, 0, "Use operator| instead") +constexpr QKeyCombination operator+(Qt::Key key, Qt::KeyboardModifier modifier) noexcept +{ + return QKeyCombination(modifier, key); +} + +QT_DEPRECATED_VERSION_X(6, 0, "Use operator| instead") +constexpr QKeyCombination operator+(Qt::Key key, Qt::KeyboardModifiers modifiers) noexcept +{ + return QKeyCombination(modifiers, key); +} +#endif + QT_END_NAMESPACE #endif // QNAMESPACE_H |